Distance=speed times time if they take the same time, we cal the time , t
b=bike speed w=walking speed
bikedistnace=17=bt walkdistance=9=wt
b is 4 more than w b=4+w
we have 17=bt 9=wt b=4w
ok so multiply first equation by 9 and 2nd by 17
153=9bt 153=17wt set equal 9bt=17wt divide both sides by t 9b=17w sub b=4+w for b 9(4+w)=17w distribute 36+9w=17w minus 9w both sides 36=8w divide both sides by 8 4.5=w
